Apparatus for drawing metal



Sept. 4, 1928. 1,683,123

' y c. BERGMANN, JR

APPARATU S FOR DRAWING METAL Filed April 18, 1925 INVENTOR Patented Sept; 4 1928.

UNITED STATES 1,683,123 PATENT QFFICE.

4 2w CARL IBERGMANN, 33., OF LYNBROOK, NEW YORK, ASSIGNOR OF ONE-HALF TO GUSTAVE R; THQMISON, OF 'NEW YORK, N. Y.

APPARATUS r03 naawme METAL.

Original application filed May 18, 1920, Serial No. 382,372. Dividcd and this application filed April 18,

1925. Serial No. 24,055.

An embodiment of said apparatus is illus trated in the accompanying drawings, wherein,

Fig. 1 is a top plan view of the forming apparatus;

Fig. 2 is a sectional view on the line 11-11 Fig. 1 looking in the direction of the arrows;

50 Fig. 3 is a face view of the die-part opposite'to that shown in Fig. 2;

Fig. 4 is a sectional view of a tampion 'or plug for closing the end of a tube which'is to be expanded or drawnin the dies.

Figs. 5, 6 and .7 are views of the "outlines or contours of dies similar to those shown in Figs. 1-3, in which successive drawing of the article is performed preliminary to eifecting the drawing in said die of Figs. 1-3.

The apparatus comprises a series of dies of successively larger sizes, corresponding to the degree to which the partially formed article is to be drawn or stretched at each stage. One of this succession of dies is shown in Figs. 13,- the die in this instance being the one in which the final drawing is elf-acted. the contours of the preceding dies of the succession being substantially as illustrated in Figs. 5-7. I

The die preferably comprises two sections or parts 1 and 2, having formed therein the ,bent and tapered'recesses 12-and 13, corresponding (together) to the form to which sections 1 and 2 preferably slide toward and i from one anotheron bolts or tie-rods 3. Th-

article to be drawn is placed between the die-parts and the die-parts brought together example, a clamp-screw 5 threaded in a yoke a fastened at one end of the bolts .or tie-rods 3, .and zloearing at its end against the die-part the article is to be drawn therein. The die l and held together by suitable means, as for.

2. A hand-wheel 6 serves the clamp-screw.'

When the article is placed in the die one end thereof is closed, the means .for this for manipulating purpose being conveniently a separate plug or tampion 15. This plug conveniently comprises a disk havin a shoulder 16 adapted to fit within a recess 1 in the die-parts 1 and 2.

'It also comprises an expansible portion 19,

or substantially tight joint between the article and the walls of the die around the passage 25. The parts 26 of the walls of the series, at the ends opposite the ends are preferably of the same sizeas the parts 25,

and hence fit tightly against the oppositeends of the tube from which the article is to be made.

Fluid (water or oil for example) pre-.

viously compressed, or not,'as may be preferred,- is then admitted to the interior of the article in the die, through the passage 25 and the open end of the article. The'pressure of the fluid, or pressure-applied thereto, if not previously compressed, expands the tubular article and draws or presses the wallspipe 30-and outwardly opening valve 31 to a cylinder 33 in communication with the passage. 25 of'the die through apart 35 and an outwardly opening valve 36. Water is admitted into the cylinder 33 and compressed therein and forced into the interior of the article in the die by means of a pis-' ton 38 conveniently mounted on the reciproeating slide of an ordinary power press. The water compressed in the article 15 or may be held therein between strokes by the 'valve 36. 1

llm

Means are preferably provided for relieving the die from increases of pressure after the article has been expanded or drawn therein due to continued actionv of the piston These means conveniently comprise a vent passage 40 communicating with the passage 25, and normally closed by a valve 42, pressed by a spring 43, the compression of which serves to keep the valve closed'under normal working pressures, but yields under excessive pressures to vent the liquid flowing through the valve 36. A sleeve 45 serves for adjusting the compression of the spring 43, and a pi e 47 serves for carrying off the vented li aid.

After t e drawing is'completed in one die, the die-parts are separated and the article removed and placed in another or other successive dies, and expanded or drawn thereln to final form, .111 a manner similar to that described.

After each' drawing operation the article is preferably annealed.

The. final form of the articleis usually roduced as a result of several acts of drawmg in a corresponding number of dies. The

tapered, bent drawn articles, com rising a series of dies adapted to successive y receive a bent tube or shell therein, each die having a tapered bent form, and being made in parts adapted to be separated and closed to admit and hold the tube or shell, means for holding the die parts to ther,- and fluid pressure means for expan g said tube or shell in said series ofrdies, each of'said dies having "at one end parts of uniform size throu bout the series adapted to fit closely aroun one end of the tube or shell to be expanded therein.

2. An apparatus for making seamless,

tapered, bent drawn articles, comprising a series of dies adapted to successively receive a bent tube or shell therein, each die having a tapered'bent form, and being made inparts adapted to be separated and closed to admit and hold the tube or shell, means for holding the die parts together, and fluid pressure means for expanding said tube or shell in said series of dies, each of said dies having at both ends thereof parts .of uniform size throughout the series adapted to fit closely'around the ends of the tube or shell to be expanded therein.

3. An apparatus for making seamless,

tapered, bent drawn articles, com rising a series of dies adapted to successlvey receive a bent tube 'or shell thereln, each die having a tapered bent form, and being made in parts adapted to be separated and closed to admit and hold the tube 01'; shell, means for holding the die parts together, means for closing one end of said tube or shell, and fluid pressure means for expanding said tube or shell 7 in said serie's'of dies. y

4. An apparatus for making seamless, tapered, bent, drawn'articles, comprlsing a die, adapted to receive a bent tube or shell therein, said die having a tapered form with a bend therein, and being made in parts adapted to be separated and closed to admit and hold the tube or shell, means for holding the die parts to ether and said die arts in closed osition bein adapted to 0 amp the ends 0 the tube or s ell, means for closing one end ofthe tube or shell, means for admitting fluid to the interior of said tube or shell, and means for compressing said fluid to cause it to expand said tube or shell against the sides of said die.

In witness whereof, I have hereunto signed my name.

CARL BERGMANN, R. 

